# `AttestoPhoenix.EventSink`
[🔗](https://github.com/XukuLLC/attesto_phoenix/blob/v0.19.0/lib/attesto_phoenix/event_sink.ex#L1)

The host-owned audit/telemetry contract.

The library emits `%AttestoPhoenix.Event{}` structs at authorization-server
milestones (token issuance, revocation, client registration, and so on) but
never stores them itself. A host implements this behaviour and wires the
callback into `AttestoPhoenix.Config` under `:on_event`; this module is the
contract that key installs and the recommended production shape. When the key
is unset, event emission is a no-op.

# `on_event`

```elixir
@callback on_event(event :: AttestoPhoenix.Event.t()) :: any()
```

Handle an authorization-server event. The return value is ignored; the host
owns persistence, metrics, and logging. The callback must not raise on the
request path (a failing audit sink should degrade, not break token issuance).

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*Consult [api-reference.md](api-reference.md) for complete listing*